Mac OS X's 'QuarantineEvents' keeps a log of all your downloads
Mac OS X users are familiar with warnings like the one shown here. Apple's "quarantine" has been in place for awhile, and it offers some minimal protection against accidentally opening files which have been downloaded from the Internet.
What most Mac OS X users probably don't know is that Mac OS X keeps a log of all files downloaded. Files are added to that log even if you are using "private" browsing in Safari or "incognito" in Google Chrome, and the log does not appear to ever be cleared.
Even so, Don't Panic: there is no evidence that this information is shared with Apple or anyone else. You do not need to be worried about Apple telling anyone that you torrented all of the episodes of Downton Abbey. The only one who has access to this information is anyone with access to your account.
